Development of the Heart

Congenital Abnormalities

Right-to-left shunts (cyanotic lesions)

• Truncus arteriosus Truncus arteriosus Truncus arteriosus (TA) is a congenital heart defect characterized by the persistence of a common cardiac arterial trunk tract that fails to divide into the pulmonary artery and aorta during embryonic development. Truncus arteriosus is a rare congenital malformation with a high mortality rate within the 1st 5 weeks of life if not managed promptly. Truncus Arteriosus: A single large vessel arises from both ventricles due to failure of formation of the aorticopulmonary septum to divide into the pulmonary trunk Pulmonary Trunk Truncus Arteriosus and aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy. Usually, it is accompanied by a VSD. Danger of irreversible pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure, which can lead to chronic progressive right heart failure. Pulmonary hypertension is grouped into 5 categories based on etiology, which include primary PAH, and PH due to cardiac disease, lung or hypoxic disease, chronic thromboembolic disease, and multifactorial or unclear etiologies. Pulmonary Hypertension. 
• TGV: Failure of the aorticopulmonary septum to spiral Spiral Computed tomography where there is continuous x-ray exposure to the patient while being transported in a spiral or helical pattern through the beam of irradiation. This provides improved three-dimensional contrast and spatial resolution compared to conventional computed tomography, where data is obtained and computed from individual sequential exposures. Computed Tomography (CT). Pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy arises from the LV (posterior), whereas the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy comes out from the RV (anterior). Unsuitable for life without a shunt. In 65% of cases, TGV is accompanied by patent ductus arteriosus Patent ductus arteriosus The ductus arteriosus (DA) allows blood to bypass pulmonary circulation. After birth, the DA remains open for up to 72 hours and then constricts and involutes, becoming the ligamentum arteriosum. Failure of this process to occur results in patent ductus arteriosus (PDA), a condition that causes up to 10% of congenital heart defects. Patent Ductus Arteriosus (PDA) or patent foramen ovale Patent Foramen Ovale A patent foramen ovale (PFO) is an abnormal communication between the atria that persists after birth. The condition results from incomplete closure of the foramen ovale. Small, isolated, and asymptomatic PFOs are a common incidental finding on echocardiography and require no treatment. Patent Foramen Ovale. In 35% of cases, it is accompanied by a ventricular septal defect Ventricular Septal Defect Tetralogy of Fallot. Radiologically will have an “egg on string” appearance on chest X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests due to narrowed mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels: Anatomy and globular heart outline. Surgical intervention is needed, otherwise most infants die within the first few months of life.
• Tricuspid atresia Atresia Hypoplastic Left Heart Syndrome (HLHS): The tricuspid valve Tricuspid valve The valve consisting of three cusps situated between the right atrium and right ventricle of the heart. Heart: Anatomy is absent, which impedes the development of the right ventricle, leading to a hypoplastic right ventricle. Requires atrial septal defect Atrial Septal Defect Atrial septal defects (ASDs) are benign acyanotic congenital heart defects characterized by an opening in the interatrial septum that causes blood to flow from the left atrium (LA) to the right atrium (RA) (left-to-right shunt). Atrial Septal Defect (ASD) ( ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder) and VSD for viability. Blood will flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure from the RA to the LA through the atrial septal defect Atrial Septal Defect Atrial septal defects (ASDs) are benign acyanotic congenital heart defects characterized by an opening in the interatrial septum that causes blood to flow from the left atrium (LA) to the right atrium (RA) (left-to-right shunt). Atrial Septal Defect (ASD) or the patent foramen ovale Patent Foramen Ovale A patent foramen ovale (PFO) is an abnormal communication between the atria that persists after birth. The condition results from incomplete closure of the foramen ovale. Small, isolated, and asymptomatic PFOs are a common incidental finding on echocardiography and require no treatment. Patent Foramen Ovale. To get to the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy, blood will flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure from the RA to the LA through the patent foramen ovale Patent Foramen Ovale A patent foramen ovale (PFO) is an abnormal communication between the atria that persists after birth. The condition results from incomplete closure of the foramen ovale. Small, isolated, and asymptomatic PFOs are a common incidental finding on echocardiography and require no treatment. Patent Foramen Ovale, and then from the LV to the RV through the ventricular septal defect Ventricular Septal Defect Tetralogy of Fallot. 
• Tetralogy of Fallot Tetralogy of Fallot Tetralogy of Fallot is the most common cyanotic congenital heart disease. The disease is the confluence of 4 pathologic cardiac features: overriding aorta, ventricular septal defect, right ventricular outflow obstruction, and right ventricular hypertrophy. Tetralogy of Fallot: Most common cause of early childhood cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination. Accompanied by pulmonary stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS), right ventricular hypertrophy Right Ventricular Hypertrophy Tetralogy of Fallot, overriding aorta Overriding Aorta Tetralogy of Fallot, and a ventricular septal defect Ventricular Septal Defect Tetralogy of Fallot. 
• Total anomalous pulmonary venous return (TAPVR): All pulmonary veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology drain into the right heart circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment (SVC, coronary sinus Coronary Sinus A short vein that collects about two thirds of the venous blood from the myocardium and drains into the right atrium. Coronary sinus, normally located between the left atrium and left ventricle on the posterior surface of the heart, can serve as an anatomical reference for cardiac procedures. Atrial Septal Defect (ASD), etc ETC The electron transport chain (ETC) sends electrons through a series of proteins, which generate an electrochemical proton gradient that produces energy in the form of adenosine triphosphate (ATP). Electron Transport Chain (ETC).). The defect is similar to the shunt from the LA to the RA. The RA and the RV cause oxygenated blood to mix with deoxygenated blood and spread throughout the body. Associated with an ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder and sometimes a PDA PDA The ductus arteriosus (DA) allows blood to bypass pulmonary circulation. After birth, the DA remains open for up to 72 hours and then constricts and involutes, becoming the ligamentum arteriosum. Failure of this process to occur results in patent ductus arteriosus (PDA), a condition that causes up to 10% of congenital heart defects. Patent Ductus Arteriosus (PDA) to allow for right-to-left shunting to maintain cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) output.

Mnemonic: right-to-left shunts (cyanotic lesions) (the 5 Ts):

• Truncus arteriosus: 1 vessel
• Transposition of the great vessels: 2 switched vessels
• Tricuspid atresia Atresia Hypoplastic Left Heart Syndrome (HLHS): 3 = tri
• Tetralogy of Fallot: 4 = tetra
• Total anomalous pulmonary venous return (TAPVR): 5 letters in the name

Left-to-right shunts ( acyanotic Acyanotic Tetralogy of Fallot)

• VSD: Most common congenital Congenital Chorioretinitis anomaly, associated with fetal alcohol syndrome Fetal alcohol syndrome An umbrella term used to describe a pattern of disabilities and abnormalities that result from fetal exposure to ethanol during pregnancy. It encompasses a phenotypic range that can vary greatly between individuals, but reliably includes one or more of the following: characteristic facial dysmorphism, fetal growth retardation, central nervous system abnormalities, cognitive and/or behavioral dysfunction, birth defects. The level of maternal alcohol consumption does not necessarily correlate directly with disease severity. Alcohol Use Disorder. The defect causes communication Communication The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups. Decision-making Capacity and Legal Competence between LV and RV. Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor is harsh, holosystolic murmur Holosystolic Murmur Tricuspid Valve Atresia (TVA) that is heard best in the tricuspid area.
• ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder:  Communication Communication The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups. Decision-making Capacity and Legal Competence between LA and RA, can lead to pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure, which can lead to chronic progressive right heart failure. Pulmonary hypertension is grouped into 5 categories based on etiology, which include primary PAH, and PH due to cardiac disease, lung or hypoxic disease, chronic thromboembolic disease, and multifactorial or unclear etiologies. Pulmonary Hypertension. Clinically characterized by wide splitting Splitting Defense Mechanisms of S2 S2 Heart Sounds. There are 4 types of ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder: primum, secundum, sinus venosus Sinus Venosus Atrial Septal Defect (ASD), and coronary sinus Coronary Sinus A short vein that collects about two thirds of the venous blood from the myocardium and drains into the right atrium. Coronary sinus, normally located between the left atrium and left ventricle on the posterior surface of the heart, can serve as an anatomical reference for cardiac procedures. Atrial Septal Defect (ASD), the most common being a secundum type of ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder.
• Patent ductus arteriosus Patent ductus arteriosus The ductus arteriosus (DA) allows blood to bypass pulmonary circulation. After birth, the DA remains open for up to 72 hours and then constricts and involutes, becoming the ligamentum arteriosum. Failure of this process to occur results in patent ductus arteriosus (PDA), a condition that causes up to 10% of congenital heart defects. Patent Ductus Arteriosus (PDA) ( PDA PDA The ductus arteriosus (DA) allows blood to bypass pulmonary circulation. After birth, the DA remains open for up to 72 hours and then constricts and involutes, becoming the ligamentum arteriosum. Failure of this process to occur results in patent ductus arteriosus (PDA), a condition that causes up to 10% of congenital heart defects. Patent Ductus Arteriosus (PDA)): Normally, ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA) shunts blood from the left pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy to the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy. This should stop after birth due to decreased levels of prostaglandin E2 Prostaglandin E2 The most common and most biologically active of the mammalian prostaglandins. It exhibits most biological activities characteristic of prostaglandins and has been used extensively as an oxytocic agent. The compound also displays a protective effect on the intestinal mucosa. Fever. Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor of PDA PDA The ductus arteriosus (DA) allows blood to bypass pulmonary circulation. After birth, the DA remains open for up to 72 hours and then constricts and involutes, becoming the ligamentum arteriosum. Failure of this process to occur results in patent ductus arteriosus (PDA), a condition that causes up to 10% of congenital heart defects. Patent Ductus Arteriosus (PDA) is a continuous machinery-like murmur on auscultation, blue toes and normal fingers, and a widened pulse pressure. 

Other congenital Congenital Chorioretinitis abnormalities

• Coarctation of the aorta Coarctation of the aorta Coarctation of the aorta is a narrowing of the aorta between the aortic arch and the iliac bifurcation commonly around the point of insertion of the ductus arteriosus. Coarctation of the aorta is typically congenital and the clinical presentation depends on the age of the patient. Coarctation of the Aorta: The aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy narrows in the area around the ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA) to a certain point and then widens to its normal diameter. Postductal coarctation (occurring after the ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA)) is clinically silent and only present in adults. Preductal coarctation (occurring before the ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA)) is an infantile type, where clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor involves cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination in the toes. 
• Patent foramen ovale Patent Foramen Ovale A patent foramen ovale (PFO) is an abnormal communication between the atria that persists after birth. The condition results from incomplete closure of the foramen ovale. Small, isolated, and asymptomatic PFOs are a common incidental finding on echocardiography and require no treatment. Patent Foramen Ovale ( PFO PFO A patent foramen ovale (PFO) is an abnormal communication between the atria that persists after birth. The condition results from incomplete closure of the foramen ovale. Small, isolated, and asymptomatic pfos are a common incidental finding on echocardiography and require no treatment. Patent Foramen Ovale): Present in 25% of adults. Failure of fusion of septum primum with septum secundum after increased left atrial pressure. Clinically detected with bubble test in evaluation of syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope and strokes. 
• Hypoplastic left heart syndrome: High-grade stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) or atresia Atresia Hypoplastic Left Heart Syndrome (HLHS) of the aortic and/or mitral valve Mitral valve The valve between the left atrium and left ventricle of the heart. Heart: Anatomy in addition to severe hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS) of the left ventricle, ascending aorta Ascending aorta Mediastinum and Great Vessels: Anatomy, and aortic arch Aortic arch Mediastinum and Great Vessels: Anatomy.
• Ebstein anomaly: Defect of the tricuspid valve Tricuspid valve The valve consisting of three cusps situated between the right atrium and right ventricle of the heart. Heart: Anatomy, which is displaced toward the right ventricle. Tethering of septal leaflet causes tricuspid regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD), which will result in right-sided heart failure Right-Sided Heart Failure Ebstein’s Anomaly. 
• Double aortic arch Double Aortic Arch Vascular Rings: Embryonic vascular malformation resulting in a double aortic arch Double Aortic Arch Vascular Rings. This can lead to subsequent constriction of the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea: Anatomy and esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus: Anatomy.
• Endocardial cushion defect: Defect of the atrioventricular valves as well as the atrial septum and/or ventricular septum. Can present as a complete form ( ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder, VSD, and severe abnormalities in the AV valves, leading to severe mixing of blood) or a partial form (only ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder and minor AV valve abnormalities). Commonly seen in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with Down syndrome Down syndrome Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21).